Display Device

1. A display device, comprising: a pixel unit including pixels divided into blocks; a timing controller configured to generate image data based on input image data; a data driver configured to generate a data signal corresponding to the image data and supply the data signal to the pixels; a power supply configured to supply a power voltage to the pixel unit; and a power controller configured to calculate a first load value corresponding to the pixels in the pixel unit, second load values corresponding to each of the blocks and first peak grayscale values corresponding to each of the blocks based on the input image data, and to generate a power control signal to change a voltage level of the power voltage based on the first load value, the second load values, and the first peak grayscale values.

2. The display device according to claim 1 , wherein a value of the power voltage decreases as a difference of the second load value between a first reference block and one or more neighboring blocks increases, the first reference block having a largest second load value among the blocks.

3. The display device according to claim 1 , wherein a value of the power voltage decreases as a difference of the first peak grayscale value between a second reference block and one or more neighboring blocks, the second reference block having a largest first peak grayscale value among the blocks.

4. The display device according to claim 1 , wherein the power controller comprises: a first load calculator configured to generate first load data by calculating the first load value; a second load calculator configured to generate second load data by calculating the second load values; and a grayscale calculator configured to generate block grayscale data by calculating the first peak grayscale values.

5. The display device according to claim 4 , wherein the first peak grayscale value corresponds to a largest grayscale value among grayscale values of a corresponding block among the blocks.

6. The display device according to claim 4 , wherein the power controller comprises: a peak grayscale reference value generator configured to generate a peak grayscale reference value based on the first load data, the second load data, and the block grayscale data; a peak grayscale value calculator configured to calculate a second peak grayscale value based on the peak grayscale reference value and the block grayscale data; and a power control signal generator configured to generate the power control signal based on the first load data and the second peak grayscale value.

7. The display device according to claim 6 , wherein the peak grayscale reference value generator comprises: a first reference value calculator configured to generate a first reference value based on the first load data; and a second reference value calculator configured to generate a second reference value corresponding to the peak grayscale reference value based on the first reference value.

8. The display device according to claim 7 , wherein the first reference value increases as the first load value increases.

9. The display device according to claim 7 , wherein the peak grayscale reference value generator comprises: a first weight calculator configured to calculate a first weight based on the second load data; a second weight calculator configured to calculate a second weight based on the block grayscale data; and a third weight calculator configured to calculate a third weight based on the first weight and the second weight, and the second reference value calculator generates the second reference value by applying the third weight to the first reference value.

10. The display device according to claim 9 , wherein a value of the first weight increases as a difference of the second load value between a first reference block and one or more neighboring blocks increases, the first reference block having a largest second load value among the blocks.

11. The display device according to claim 9 , wherein a value of the second weight increases as a difference of the first peak grayscale value between a second reference block and one or more neighboring blocks, the second reference block having a largest first peak grayscale value among the blocks.

12. The display device according to claim 9 , wherein the third weight calculator is configured to extract a first reference block and a second reference block having a largest first peak grayscale value among the blocks, the first reference block having a largest second load value among the blocks and the second reference block having a largest first peak grayscale value among the blocks.

13. The display device according to claim 12 , wherein the third weight calculator is configured to calculate the third weight by adding the first weight and the second weight when the first reference block is same as the second reference block.

14. The display device according to claim 12 , wherein the third weight calculator is configured to calculate the third weight having a value of 0 when the first reference block is different from the second reference block.

15. The display device according to claim 9 , wherein the second reference value calculator generates the second reference value by adding the third weight to the first reference value.

16. The display device according to claim 6 , wherein the peak grayscale value calculator is configured to calculate, as the second peak grayscale value, a first peak grayscale value that satisfies the peak grayscale reference value among the first peak grayscale values in the block grayscale data.

17. The display device according to claim 6 , wherein a value of the power voltage increases as the first load value increases based on the power control signal.

18. The display device according to claim 6 , wherein a value of the power voltage increases as the second peak grayscale value increases based on the power control signal.

19. The display device according to claim 7 , wherein the grayscale calculator is configured to generate grayscale ratio data based on the input image data.

20. The display device according to claim 19 , wherein the peak grayscale reference value generator comprises a reference value controller configured to generate a reference value control signal to control a size of the first reference value based on the grayscale ratio data.